Respiratory syncytial virus (RSV) is an enveloped RNA virus that is the most important viral agent of pediatric respiratory tract disease worldwide. It currently lacks a licensed vaccine. RSV is a member of the paramyxovirus family of Order Mononegavirales, the nonsegmented negative strand RNA viruses, and RSV is the most complex member of the group. This large group of viruses includes important pathogens such as measles, mumps, rabies and Ebola viruses. Knowledge of the organization and expression of the RSV genome would help guide efforts to make attenuated recombinant viruses as vaccines, which is the major goal of related projects in this laboratory. We previously sequenced the 15,222-nucleotide genome of RSV, mapped its genes and its transcription signals, and analyzed its mechanism of gene expression. We currently are performing detailed mutagenic and functional analysis of the promoters and encapsidation signals at the 3 end of genomic and antigenomic (replicative intermediate) RNA. - Virus, vaccine, live- attenuated viral vaccine, pediatrics, infectious disease, respiratory tract disease, recombinant DNA